Isolation and Characterization of Extracellular Vesicles Derived from Human Umbilical Cord Mesenchymal Stem Cells

The safety and efficacy of mesenchymal stem cells/marrow stromal cells (MSC) have been widely studied. Since they are hypoimmunogenic, MSC can escape immune recognition, thus making them an attractive tool in clinical settings beyond autologous cell-based therapy. Paracrine factors including extracellular vesicles (EVs) released by MSC play a significant role in exerting therapeutic effects of MSC. Since their first discovery, MSC-EVs have been widely studied in an attempt to tackle the mechanisms of their therapeutic effects in various disease models. However, currently there are no standard methods to isolate EVs. Here, we describe a differential centrifugation-based protocol for isolation of EVs derived from human umbilical cord MSC (huc-MSC). In addition, the protocol describes methods for characterization of the EVs using transmission electron microscope, Western blot, and nanoparticle tracking analysis.